The present invention relates to a single-fin fastener for attaching a base member to the hole of another member such as a panel.
FIG. 1 shows a conventional single-file fastener B comprising a support board 1 integrally formed on a synthetic resin base member A and projecting therefrom, and an engaging fin 3 having a flexible hinging butt 2 at the tip of the support board 1 and extending from the tip of the board 1 in a direction opposite to that of the projection of the board. The engaging fin 3 includes an engaging notched portion 3a near the movable tip of the fin. FIG. 2a shows the state that the synthetic resin base member A is attached to the hole 4 of a panel C by the single-fin fastener B. When a force F of 4 to 5 kg acts on the base member A in such a direction as to pull the member out of the hole 4 of the panel C, as shown in FIG. 2B, stress concentrates on the structurally weakest flexible hinging butt 2 so that the engaging fin 3 is opened to a limit. As a result, the single-fin fastener B is easily pulled out of the hole 4 of the panel C, starting with the support board 1 of the fastener. This is a problem.